The goal of anti-infective stewardship is to select therapies that optimize the probability of positive outcomes for patients suffering from an infection. The primary focus of anti-infective stewardship is the optimal selection of anti-infective therapy, including dose, dosing interval, and duration. Due to the emergence of anti-infective-resistant pathogens, selecting optimal anti-infective therapy is more complex than at any other time since the advent of penicillin.